Describe the Bohr model for the atom. How did the Bohr

Solution Step 1 Explanations for each of the statements are as given below (i)Effective nuclear charge is that portion of charge that a given electron in an atom experiences.It is the net electrical field experienced by the electron Z* = Z- Where Z= the atomic number of the element( the number of positively charged protons in the nucleus) = screening factor dependent on other electrons present in an atom (ii)When we move from left to right along the periodic table,the nuclear charge or the number of protons increases but the outermost electron is getting added to the same shell .Hence the contibution to screening factor is less when compared to increase in the value of Z.Thus effective nuclear charge increase as move move from left to right in a period (iii)This is an incorrect statement .Core electrons contribute to shielding more than valence electrons (iv) The effective nuclear charge shows a sudden decrease when we go from the end of one row to the beginning of the next row of the periodic table because a new shell is being added .Screening of core electrons are greater than those of inner electrons. (v)The change in effective nuclear charge is lesser down the group however it increases slightly as we go down a column because the more diffuse core electron cloud is less able to screen the valence electrons from the nuclear charge.